Manti Te'o says that even though he was hoaxed by the supposed existence of a fake girlfriend, his inspirational story of playing through emotional pain "was all real and that's something that I can't fake."

Te'o made his comments to Katie Couric which will air the exclusive interview on Thursday.

Te'o, 21, has been alternately questioned and lampooned over his role in the hoax that led him and the public to believe that his girlfriend Lennay Kekua died of leukemia as Te'o led the Notre Dame football team to an undefeated season that culminated in the national championship game.

Te'o was also a finalist for the Heisman Trophy, which goes to the best college football player in the country. Couric asked the star linebacker whether the emotional "story line" of a girlfriend who died on the same day as his grandmother "helped propel you to second place in Heisman voting?"

"I don't know. I really don't know," Te'o replied.

See more exclusive previews tonight on "World News With Diane Sawyer" and "Nightline."

He was more certain, however, when Couric pressed him by pointing out that it had become "sort of a legend that you had endured this hardship and gone on to play your team and your school to victory... Did you feel like, wow, I'm getting a lot of attention for this?"

"I think for me the only thing I basked in was that I had an impact on people, that people turned to me and for inspiration and I think that was the only thing I focused on. You know my story I felt was a guy who in times of hardship and in times of trial really held strong to his faith, held strong to his family and I felt that that was my story," said Te'o, who is a Mormon.

Te'o said there was no acting in his emotions at the time when he thought the girl he called "Lala" had died of leukemia.

"What I went through was real. You know the feelings, the pain, the sorrow, that was all real and that's something that I can't fake," he said.

During the interview, Te'o said that he received a phone call on Dec. 6, apparently from the same woman he believed was dead, who told him she was alive. She said that her name was not Lennay Kekua, it was Leah. Teo has also said that woman sent him a different picture of herself.

Nevertheless, he again publicly mentioned his girlfriend, and her death, two days later on the day the Heisman trophy was to be awarded.

"You stuck to the script. And you knew that something was amiss, Manti," Couric said.

"Katie, put yourself in my situation. I, my whole world told me that she died on Sept. 12. Everybody knew that. This girl, who I committed myself to, died on Sept. 12," Te'o said.

"Now I get a phone call on Dec. 6, saying that she's alive and then I'm going be put on national TV two days later. And to ask me about the same question. You know, what would you do?" Te'o said.

Te'o was joined by his parents, Brian and Ottilia, in the interview.

"Now many people writing about this are calling your son a liar. They are saying he manipulated the truth, really for personal gain," Couric said to Te'o's father.

"People can speculate about what they think he is. I've known him 21 years of his life. And he's not a liar. He's a kid," Brian Te'o said with tears in his eyes.

Diane O'Meara told NBC's "Today" show Tuesday that she was used as the "face" of the Twitter account of Manti Te'o's online girlfriend without her knowledge or consent.

O'Meara said that Ronaiah Tuiasosopo used pictures of her without her knowledge in creating Kekua.

"I've never met Manti Te'o in my entire life. I've never spoke with him. I've never exchanged words with him," O'Meara said Tuesday.

Manti Te'o Talks With Katie Couric

The 23-year-old marketing executive went to high school in California with Tuiasosopo, but she says they're not close. Tuiasosopo called to apologize the day Deadspin.com broke the hoax story, she said.

In an interview with ESPN last week, Te'o said he had received a Twitter message from Tuiasosopo apologizing for the hoax.

The Hawaiian also spoke to Tuiasosopo on the phone the day the Deadspin report came out, according to ESPN.com. He found out that "two guys and a girl are responsible for the whole thing," he said.

But he did not know the identities of the other individuals involved, other than the man he says was Tuiasosopo.

Tuiasosopo, a 22-year-old resident of California, has not admitted involvement publicly. Tuiasosopo graduated from Paraclete High School in Lancaster, Calif., in 2007 and has posted dozens of videos online singing Christian songs.

Those who knew him say he was a devout Christian and a good athlete. His former football coach Jon Flemming described him as gregarious, and from a "good loving family." Flemming said Tuiasosopo is the kind of guy who gives you a hug when he sees people he knows.